I dont have mobile data when booting to ROM. It doesn't show GSM connection.
A: In first boot, when asked to "Consent for Diagnostic Report", you have to uncheck it, as written in OP. To solve it:
1. Power off phone
2. Remove sim card
3. Boot to ROM.
4. Go to settings/general management
5. Disable "Report Diagnostic Info"
6. Power off Device.
7. Insert sim card.
8. Boot up phone and continue using it